treatments/LAUNAEA

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LAUNAEA Cassini in F. Cuvier, Dict. Sci. Nat. ed.. 2, 25: 61, 321. 1822.

[For J. Cl. M. Mordant de Launay, 1750–1816, lawyer, later librarian at Musée d’Histoire Naturelle, Paris]

R. David Whetstone, Kristin R. Brodeur,

Annuals or biennials [perennials, shrubs, sometimes spiny], [5–]30–150 cm; usually taprooted [stoloniferous]. Stems erect [prostrate], distally branched, glabrous [± hairy]. Leaves basal or basal and proximally cauline; petiolate or sessile; blades ± oblanceolate, often pinnately lobed, ultimate margins usually dentate (teeth usually ± prickly; faces glabrous [± hairy]). Heads in spiciform or racemiform to paniculiform arrays [borne singly]. Peduncles not inflated distally, bracteolate. Calyculi 0 (or bractlets intergrading with phyllaries). Involucres cylindric [urceolate, campanulate, or obconic], 3–5[–16] mm diam. Phyllaries (persistent, reflexed in fruit) 18–25 in 3–5+ series, unequal, ovate to lanceolate (outer) or linear (inner), margins scarious, apices obtuse to acuminate (faces glabrous [± hairy]). Receptacles flat to convex, epaleate. Florets 25–30; corollas yellow to ochroleucous [cyanic]. Cypselae blackish to grayish, cylindric to fusiform or ± prismatic, sometimes ± compressed, beaks 0 (or lengths 0.05–0.1 times bodies), 4–5-ribbed (or -grooved), ribs usually muricate, faces glabrous; pappi persistent or tardily falling [readily falling], double [simple], of 60–100+, outer, white, often ± coiled or crisped (frizzy) hairs or bristles in 2–3 series plus 80–120+, white, coarser, barbellulate to smooth bristles in 2–3+ series, all distinct or some basally connate. x = 9.


Species ca. 50 (1 in the flora):Mexico; West Indies; Central America; South America; introduced also in Europe; n Africa; Atlantic Islands; sw; c Asia.;


SELECTED REFERENCES
Kilian, N. 1997. Revision of Launaea Cass. (Compositae, Lactuceae, Sonchinae). Englera 17.